This invention relates to an improved building construction for domes or other spherical frames.
Domes are attractive architectural shapes, but their use has been limited because they are generally expensive to construct. In conventional dome construction, the frame of the dome consists of many different sizes of struts, with the number of different sizes growing larger as the dome size increases for a given maximum length of the struts. For example, the geodesic dome frame by Fuller, described in U.S. Pat. No. 2,682,235, requires five different lengths of struts for a 4-frequency dome (the edge of the regular icosahedron divided into four) and requires 56 different strut lengths for a 16 frequency dome. In the larger domes where higher frequencies are utilized, the lamella system described in U.S. Pat. No. 2,908,236, and employed in the Astrodome in Houston, Tex., enables the use of fewer different strut lengths. The lamella system has been used to construct spherical roof frames of up to 640 feet clear span, using only 14 different lengths of girders. While these systems reduce the cost of dome structures as compared to other coventional designs, they still require many different frame elements of large size and require precise fabrication of these elements, which leads to a relatively high cost for dome structures. An important cost-contributing factor is that highly skilled workmen are required in order to properly assemble dome structures that have many large size, slightly different elements.